The president of Taiwan has said that political progress in mainland China is unstable. Speaking in a rare interview with the BBC, Ma Ying-jeou said he was disappointed that despite improvements in the economic relationship during his two terms as president, there had been no meeting between himself and President Xi Jinping of China.

"Mainland China is only 100 nautical miles away from the Republic of China (Taiwan). Therefore it's a big risk and a big opportunity for us. Any leader here has to learn how to minimise the risks and maximise the opportunity. That's what I've been doing for the past seven years," he said.

The Chinese government claims the island of Taiwan as part of its sovereign territory and threatens to counter any move to outright independence by military force.

The first time I visited Taiwan in the early 1990s, there were no direct flights from Beijing. Along with everyone else, I had to make a long-distance dog-leg via Hong Kong.

In those days, Beijing was still a low-rise city of coal dust, brick alleys and bicycles. Taipei felt glossy and high-rise by comparison. How things have changed. There are now more than a hundred flights every day across the Taiwan Strait, Beijing is a city of glass and concrete canyons, and China bestrides the global economy.

At a conference in Ethiopia this week, the world is discussing the funding for a new set of international goals on sustainable development. Any global attempt to push for sustainability will need the world's biggest country on board. China represents a fifth of the world's population, and after more than three decades of high speed growth it is grappling with the challenge of cleaning up environmental damage and creating a more sustainable future. China Editor Carrie Gracie visited Hunan Province in central China to assess the progress of the cleanup there.

Water should be a life giver. But in the fields of Zhubugang it is a silent killer.

It's exactly two years since the door of Peter Humphrey's Shanghai bedroom was kicked in by police and he disappeared into a prison nightmare which ended only three weeks ago with his deportation from China.

In an exclusive interview with the BBC, the British corporate investigator who became embroiled in GlaxoSmithKline's (GSK) China corruption scandal tells me his story is "a cautionary tale which many people can learn from".